Algarve Centre for Marine Sciences

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Roots and rhizomes of wild Asparagus: nutritional composition, bioactivity and nanoencapsulation of the most potent extract

Publication . Adouni, Khaoula; Júlio, Ana; Santos-Buelga, Celestino; González-Paramás, Ana M.; Filipe, Patrícia; Rijo, Patricia; Costa Lima, Sofia A.; Reis, Salette; Fernandes, Ângela; Ferreira, Isabel C.F.R.; Fernández-Ruiz, Virginia; Morales, Patricia; Flamini, Guido; Achour, Lotfi; Fonte, Pedro

The nutritional composition and bioactive properties of roots and rhizomes of Asparagus stipularis were evalu- ated. Antioxidant activity of extracts obtained by infusion was evaluated using free radicals scavenging and reducing power methods. Porcine liver primary cell was used to check the hepatotoxicity of infusions. Results revealed that Asparagus samples are likely a source of nutrients, such as dietary fibre and essential fatty acids. HPLC-DAD-ESI/MS characterization of infusions allowed the identification and quantitation of 7 phenolic compounds, all hydroxycinnamoyl derivatives, with caffeic acid as the most abundant. Roots infusion contained the highest amounts of these compounds. It also exhibited the highest antioxidant activity in all assays, with EC50 values of 0.44 ± 0.01, 0.98 ± 0.03 and 0.64 ± 0.01 mg/mL for DPPH, ABTS and FRAP assays, respectively, with no toxicity towards PLP2 primary cell cultures (GI50 > 400 μg/mL). PLGA nanoparticles loaded with root extract were prepared using solvent-evaporation double emulsion method. Nanoparticles size was about 260 nm and a polydispersity index around 0.1, with a zeta potential of about -36 mV, as well as a good encapsulation efficiency of approximately 83%. Their morphology was analysed by SEM and spherical polymeric nanoparticles with a smooth surface were observed. FTIR and DSC were also performed, which allowed corroborating the efficacy of the encapsulation and to confirm the production of a stable and robust system to load Asparagus extracts. The developed nanoparticles are expected to be used as delivery systems for bioactive compounds of A. stipularis and they could be used as an innovative dietary supplement.

2022Journal article

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What do oysters smell? Electrophysiological evidence that the bivalve osphradium is a chemosensory organ in the oyster, Magallana gigas

Publication . Rato, Ana; Joaquim, Sandra; Matias, Domitília; Hubbard, Peter

The sensing of chemical cues is essential for several aspects of bivalve biology, such as the detection of food and pheromones. However, little is known about chemical communication systems in bivalves or the possible role of the osphradium as a chemosensory organ. To address this, we adapted an electrophysiological technique extensively used in vertebrates & mdash;the electro-olfactogram & mdash;to record from the osphradium in the Pacific oyster, Magallana gigas. This technique was validated using amino acids as stimulants. The osphradium proved to be sensitive to most proteinogenic l-amino acids tested, evoking tonic, negative, concentration-dependent 'electro-osphradiogram' (EOsG) voltage responses, with thresholds of detection in the range of 10(-)(6) to 10(-)( 5) M. Conversely, it was insensitive to l-arginine and l-glutamic acid. The current study supports the hypothesis that the osphradium is, indeed, a chemosensory organ. The 'electro-osphradiogram' may prove to be a powerful tool in the isolation and characterization of pheromones and other important chemical cues in bivalve biology.

2023-01Journal article

Open Access

DNA barcoding reveals cryptic diversity, taxonomic conflicts and novel biogeographical insights in Cystoseira s.l. (Phaeophyceae)

Publication . Neiva, J.; Bermejo, Ricardo; Medrano, Alba; Capdevila, Pol; Milla-Figueras, David; Afonso, Pedro; Ballesteros, Enric; Sabour, Brahim; Serio, Donatella; Nóbrega, Eduardo; Soares, João; Valdazo, José; Tuya, Fernando; Mulas, Martina; Israel, Álvaro; Sadogurska, Sofia S.; Guiry, Michael D.; Pearson, Gareth; Serrao, Ester

Cystoseira sensu lato (s.l.) - encompassing the genera Cystoseira sensu stricto (s.s.), Ericaria and Gongolaria - is a diverse group of forest-forming brown macroalgae endemic to the warm-temperate North-east Atlantic. These algae have immense biogeographic and ecological significance and have been experiencing recent regional declines. Most Cystoseira s.l. display important morphological plasticity and can be confused with similar species. Therefore, species boundaries, geographic ranges and phylogenetic affinities remain imprecise for most. In the face of persistent taxonomic difficulties, several authors underlined the necessity for new molecular-based approaches, but studies so far lacked representativity, resolution and standardization. To fill in these gaps, in this study we sequenced a comprehensive collection of Cystoseira s.l. spanning its entire North-east Atlantic range for a similar to 1200 bp cox1 barcode, and sequenced selected individuals representing major genetic entities for a few additional plastid markers. Phylogeographic, phylogenetic and species delimitation methods revealed 27 Molecular Operational Taxonomic Units, including unaccounted cryptic diversity, and elucidated with unprecedented resolution species compositions and phylogenetic relationships within each genus. Some entities within the lineages Cystoseira compressa/humilis, Ericaria brachycarpa/crinita, E selaginoides and tophulose Gongolaria, as well as among free-living algae, conflicted with a priori taxonomic assignments, and required the redefinition, reinstatement and recognition of new taxa. For some, diagnostic mutations and biogeography were more useful for species identifications than morphological characters or conventional barcoding gaps. A few species showed narrow geographic ranges and others were the sole representatives of their respective lineages. Several sister-species showed Atlantic vs Mediterranean complementary ranges. phylogenetic signal of coxl was nevertheless insufficient to confidently determine patterns of lineage splitting in several lineages and species complexes and did not improve significantly with additional plastid markers. We discuss novel systematics and biogeography insights considering the advantages and shortcomings of the barcoding approach employed, and how this comprehensive baseline study can be expanded to address multiple questions still left unanswered.

2022Journal article

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European marine omics biodiversity observation network: a strategic outline for the implementation of omics approaches in ocean observation

Publication . Santi, Ioulia; Beluche, Odette; Beraud, Mélanie; Buttigieg, Pier Luigi; Casotti, Raffaella; Cox, Cymon J.; Cunliffe, Michael; Davies, Neil; de Cerio, Oihane Diaz; Exter, Katrina; Kervella, Anne Emmanuelle; Kotoulas, Georgios; Lagaisse, Rune; Laroquette, Arnaud; Louro, Bruno; Not, Fabrice; Obst, Matthias; Pavloudi, Christina; Poulain, Julie; Præbel, Kim; Vanaverbeke, Jan; Pade, Nicolas

Marine ecosystems, ranging from coastal seas and wetlands to the open ocean, accommodate a wealth of biological diversity from small microorganisms to large mammals. This biodiversity and its associated ecosystem function occurs across complex spatial and temporal scales and is not yet fully understood. Given the wide range of external pressures on the marine environment, this knowledge is crucial for enabling effective conservation measures and defining the limits of sustainable use. The development and application of omics-based approaches to biodiversity research has helped overcome hurdles, such as allowing the previously hidden community of microbial life to be identified, thereby enabling a holistic view of an entire ecosystem's biodiversity and functioning. The potential of omics-based approaches for marine ecosystems observation is enormous and their added value to ecosystem monitoring, management, and conservation is widely acknowledged. Despite these encouraging prospects, most omics-based studies are short-termed and typically cover only small spatial scales which therefore fail to include the full spatio-temporal complexity and dynamics of the system. To date, few attempts have been made to establish standardised, coordinated, broad scaled, and long-term omics observation networks. Here we outline the creation of an omics-based marine observation network at the European scale, the European Marine Omics Biodiversity Observation Network (EMO BON). We illustrate how linking multiple existing individual observation efforts increases the observational power in large-scale assessments of status and change in biodiversity in the oceans. Such large-scale observation efforts have the added value of cross-border cooperation, are characterised by shared costs through economies of scale, and produce structured, comparable data. The key components required to compile reference environmental datasets and how these should be linked are major challenges that we address.

2023Journal article

Open Access

Field studies of seahorse population density, structure and habitat use in a semi-closed north-eastern Mediterranean marine area (Stratoni, north Aegean Sea)

Publication . Correia, Miguel; Paulo, Diogo; Samara, Elina; Koulouri, Panayota; Mentogiannis, Vasilis; Dounas, Costas

The present study was carried out in the marine area of Stratoni, Greece, where two seahorse species are present (Hippocampus hippocampus and H. guttulatus). Two surveys were conducted (September 2016, May 2019) to gather information regarding seahorse species’ abundance, distribution and habitat characteristics. Four different seahorse natural and artificial habitat types were identified. Results revealed that the abundance of H. hippocampus was relatively high, especially at sites with artificial structures, while the presence of H. guttulatus was rare. Data collected can provide baseline information for future population assessments.

2020-05-08Preprint

Open Access